This invention relates to a method of construction of a roof system as adapted to new building construction and reroofing requirements.
Present roof designers provide built-up roofing construction, whereby the roof deck supports multiple weatherproof membrane layers of materials. The membrane materials are normally asphaltic felt membranes having bituminous adhesion between and bituminous material providing the adhesion of the lower membrane to the roof deck itself. The multiple layer method provides a minimal insulation; however, such construction elements are unrelated to the insulation property requirements for the roof design.
The requirement for insulated roofs for buildings further demands providing insulation which may be comprised of the various materials, such as styrofoam sheets, plywood sheets or other comparable construction insulation products.
The top surface (exposed) of a normal roof system provides for an asphaltic mastic and granules 24 layer combination which resists the sun's (ultra-violet rays), as well as heat and cold changes which affect the durability of the roof system itself. The IRMA system, substantially shown as U.S. Pat. No. 3,411,256, discloses the method of roof construction adapted by architects and engineers for buildings requiring a warranty as to life for the roof.
Such a system comprises providing a permeable membrane immediately adjacent to the roof deck which normally consists of a plurality of alternating layers of felt and a bituminous material. A thermo-insulating layer is placed over the multiple membranes of felt layers. This insulating layer is, in most instances, both water resistant and, to a degree, water impermeable. A further protective layer of mastic and granules is applied to provide the top exterior surface of the finished roof.
The present concern in the industry and among property owners for providing a roof having characteristics for a long period of quality retention, with limited repair needs, has been accentuated by a number of various serious and expensive roof accidents and fires which have damaged properties and their contents because of inadequate or incorrect roof construction.